HEXAHYDRO-3,3,6,6-TETRA ALKYLFURO(3,2-b)FURAN-2,5-DIOL

ABSTRACT

Novel bicyclic furofuran-diols having the structure:   WHEREIN R1 and R2 are the same or different, and each of R1 and R2 are alkyl groups of one to 10 carbons, have been discovered. The compounds are valuable intermediates, for the preparation of polyols, dilactones, simple esters and polyesters.

United States Patent Hagemeyer, Jr. et al.

HEXAHYDRO-3,3,6,6-TETRA ALKYLFURO(3,2-B)FURAN-2,5-DIOL Hugh J. l-lagemeyer, Jr.; Alfred G. Robinson, Ill, both of Longview, Tex.

inventors:

Eastman Kodak Company, Rochester,

Filed: June 10, 1970 Appl. No.: 45,218

Assignee:

References Cited OTHER PUBLICATIONS Ali et al., Chem. Abstracts 1958) Vol. 52, 11790C.

Primary E.\-aminer-Alex Mazel Assistant Examiner-Bernard Dentz Attorney-Cecil D. Quillen, Jr. and Daniel B. Reece, Ill

[57] ABSTRACT Novel bicyclic furofuran-diols having the structure:

\CCH O HO-CH \CHOH O H(lJ\ wherein R and R are the same or different, and each of R and R are alkyl groups of one to 10 carbons, have been discovered. The compounds are valuable intermediates, for the preparation of polyols, dilactones, simple esters and polyesters.

6 Claims, No Drawings HEXAHYDRO-3 ,3 ,6,6-TETRA ALKYLFUROO ,2- B)FURAN-2,5-DIOL This invention relates to novel dihydroxy ethers and to a method of Preparing the Compounds- More particularly, the 5 such as sodium methoxide,sodium ethoxide, sodium isobutoxinvention is directed to a novel class of bicyclic furofuran-diol ide, otassium methoxide, potassium ethoxide. potassium compounds and their preparation. isobutoxide, etc., with the furodioxol-ol. The reaction The bicyclic furofuran-diols of the invention have the folproceeds at ambient temperatures but temperatures slightly lowing structure: above or below room temperature may be used, if desired. Or- R R 10 dinarily, the base is added incrementally to the bicyclic furodioxol-ol compound at a temperature in the range of about C. to 35 C., and preferably C. to 15 C. The base is HO CH CHTOH added in an amount sufficient to catalyze the reaction, 0-- 11-0 generally about 0.1 to 15 weight percent, preferably 5 to weight percent based on the weight of alkali metal alkoxide. A stirred reactor is advantageously employed for the reaction to wherein R and R are the same or different and each of R provide more efficient contact between the catalyst solution and R are alkyl groups of one to 10 carbon atoms and and the bicyclic furodioxol-ol. preferably from one to four carbon atoms. The bicyclic fu- The novel bicyclic furofuran-diols of the invention unexpecrofuran-diol compounds are particularly useful for the tedly have been found to exhibit unusual stability toward repreparation of simple esters and polyesters. The compounds agents which ordinarily are known to react with hemiacetals, of the invention also find use as intermediates in the formation despite the fact that two hemiacetal linkages are present in the of polyols and dilactones. Polyols are widely used chemicals novel compounds. For example, hemiacetals as a class react having utility as humectants and as components of such valuareadily with hydroxylarnine to form the corresponding oximes. ble materials as resinous materials such as polyvinyl chloride This reaction is normally carried out at room temperature and compositions. Lactones are known to homopolymerize into is complete within 15 minutes to 2 hours. By contrast, the useful surface coating materials such as waxes and polishes compounds of the invention are inert to hydroxylamine after and to react with difunctional organic compounds such as an 18 hour reaction time. Exactly the same phenomenon is obdihydric alcohols and diamines to fonn polyesters useful, for served using Tollens reagent (silver mirror test). As a class, instance, as plasticizers. hemiacetals react almost instantaneously. The compounds of It has been unexpectedly found that the bicyclic furofuranthe invention, however, fail to form a silver image after an l8 diol compounds of the invention may be obtained by the basehour period. The unusual stability of the compounds of the incatalyzed rearrangement of a bicyclo furodioxole compound vention is dramatically shown by the following comparative having the general structure: data:

Time required Compound Reagent for reaction CH3 CH3 Hydroxylamine 30 minutes.

C-CH-O CH3 HO-CH CHCH O-CH-O CH:

Tetrahydro-2-isopropyl-6,fi-dimethyll'uro- [2,3-d1-1 ,3-dioxol-5-ol.

Tollens reagent..." 2 minutes (as evidenced by appearance of silver mirror).

CH; CH; Hydr0xylamine N0 reaction in 8 hours.

C'C H-O H O-CH CH-OH O C HC C H3 C H3 Hexahydr0-3,3,6,G-tetramethylfuro[3,2-b]furan- Tollens reagent. No silver mirror 2,5-diol. in 18 hours.

wherein R and R are as defined above. The rearrangement of furodioxol-ol to furofuran-diols by base catalysis rearrangement reaction of the invention can be illustrated by the following equation:

wherein R and R are as previously defined.

The base-catalyzed condensation of the aldehydes having a single alpha hydrogen atom and glyoxal to form the bicyclic furodioxole starting material according to the process of this invention is effected by contacting an aqueous mixture of the aldehyde and glyoxal in a ratio of at least 2 moles of aldehyde per mole of glyoxal in the presence of an aqueous solution of alkali metal carbonate or alkali metal acetate at a temperature between C. and 50 C. Although not necessary, the reaction is preferably conducted in an inert atmosphere, e.g., nitrogen. Air or oxygen are preferably excluded from the reaction system. The product can be recovered from the reaction mixture by any suitable means such as by vacuum distillation.

Under certain conditions it may be desirable to dissolve the bicyclo furodioxole compound in a suitable solvent such as, for example, ethanol although the use of such a solvent is not necessary. It is also desirable that the base catalyst be neutralized after the reaction has been completed. This can be accomplished by simply adding the appropriate amount of any suitable acid.

Aldehydes suitable for use in preparation of the bicyclic furodioxoles are those having a single alpha hydrogen atom. These aldehydes can be considered as derivatives of acetaldehyde and can be represented by the formula:

R2 w-oa-cao the aqueous base according to the following equation to form 3 tetrahydro-Z-isopropyl-6,6-dimethylfuro-[2,3-d]-1,3-dioxol- 5 -ol:

in carrying out the reaction for the preparation of the bicyclic furodioxoles, the aqueous base is usually added incrementally to an aqueous mixture of aldehyde and glyoxal. The reaction is exothermic and can be effected at temperatures between l0 C and 50 C., preferably between C and C. Suitable bases to effect the condensation include any alkali metal carbonate or acetate. The alkali metal carbonates and, in particular, potassium or sodium carbonate, are preferred catalysts. The concentration of the aqueous base is not critical and is generally employed in amounts of from I to 15 weight percent, preferably 3 to 8 weight percent, based on total charge. Good results are obtained by employing stoichiometric amounts of aldehyde and glyoxal, i.e., mole ratio of aldehydezglyoxal of 2:1, although higher ratios can be employed. The reaction is preferably conducted in a stirred reactor to improve contact of the reactants and catalyst solution.

As aforementioned, the novel bicyclic furofuran-diols invention are useful intermediates for the preparation of polyols and dilactones by the following syntheses:

1. Preparation of 2,2,5 ,S-Tetraalkyl-l ,3,4,6-hexanetetrol wherein R and R are as previously defined.

2. Preparation of 3,4-Dihydroxy-2,2,5,S-tetraalkyladipic acid dilactone wherein R and R are as previously defined.

In addition the novel bicyclic furofuran-diols are useful for the preparation of simple and polyesters in accordance with the following reactions:

1. Preparation of Simple Esters wherein R is a suitable anhydride radical and R and R are as previously defined.

wherein R and R are suitable anhydrides and R and R are as previously defined and wherein X is from 2 to 15.

The invention will be further illustrated by the following examples and it should be understood that the examples are set forth for purposes of illustration only and are not to be construed as limiting the invention in any manner.

EXAMPLE 1 Preparation of Starting Material Tetrahydro-2-lsopropyl-6,6-

Dimethylfuro-[2,3-d]-l,3-Dioxol-5-ol To a stirred mixture in a nitrogen atmosphere consisting of 6000 ml. of water, 1800 g. (25 moles) of isobutyraldehyde and 1800 g. 12.4 moles) of glyoxal is added dropwise a solution of 450 g. of potassium carbonate dissolved in 450 g. of water. The time required for addition is 2 hours. As addition proceeds, the temperature increases from 24 C. to a maximum of 42 C. After addition is complete, the mixture is stirred for 4 additional hours. The resulting organic layer is separated from the reaction mixture. After washing once with its own volume of water, the crude product is heated to 50 C. at reduced pressure to remove water and unreacted aldehydes. The weight of isobutyraldehyde recovered is 263 g. The base product solidifies to give a white waxy solid, mp. 57

. C to 59 C. The weight of the product obtained is 2020 g.

moles). The product structure assignment as tetrahydro-2- isopropyl-6,6-dimethylfuro-[2,3-d1-l,3-dioxol-5-ol is based on the following analytical data:

described in copending US. Pat. Application Ser. No. 798,803 filed Feb. 12, 1969, now US. Pat. 3,564,017 which is incorporated herein by reference.

EXAMPLE 2 Preparation of Hexahydro-3,3,6,6-Tetramethylfuro[3,2-b]Furan-2,5-Diol To a stirred mixture consisting of 50 grams (0.247 mole) of tetrahydro-Z-isopropyl-6,6-dimethyl-[ 2,3d]-l ,3-dioxol-5-ol prepared as described in Example 1 above, and 100 ml. of absolute ethanol is added dropwise at room temperature 1000 ml. of 0.25N alcoholic sodium ethoxide over a 2-hour period. After addition is complete, the reaction mixture is stirred for 4 additional hours. Sufficient concentrated HCl is added to neutralize the catalyst. Ethanol is removed under reduced pressure and the residue dissolved in 200 ml. acetone. The precipitated salts are separated by filtration. Acetone is removed by heating the filtrate on a steam bath. The resulting brown-red solid is recrystallized from an ether-acetone mixture to give 37.5 grams (75 percent conversion) of hexahydro- We claim: 1. A bicyclic furofuran-diol compound having the structure:

\C{CHO HOCH CH-OH O HC/ wherein R and R are the same or different and each of R and R are alkyl groups of one to four carbon atoms.

2. The compound of claim 1 wherein R and R are methyl groups.

3. l-lexahydro-3,3,6,6-tetramethylfuro[3,2-b]furan-2,5-diol.

4. A method for preparing a bicyclic furofuran-diol having the structure \CCHO H /CH-OH \O H-C wherein R and R are the same or different and each of R and R are alkyl groups of one to four carbon atoms which comprises contacting an alkali metal alkoxide catalyst with a bicyclic fuordioxole compound having the structure:

wherein R and R have the same value as described above.

5. The process of claim 4 wherein the catalyst is sodium ethoxide.

6. The process of claim 5 wherein bicyclic compound contacted is tetrahydro-2-isopropyl-6,6-dimethylfuro[2,3-d1-l ,3- dioxol-S-ol.

'P0-1050 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTICN PatemNO. 3,671,550 Dated Jun 20 1972 Inventgr(s) Hugh J. Hagemeyer, Jr. and Alfred G. Robinson Ill It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[ Column l,llineg 58-63, the formula should. read: 7 T

c ca-o P R HO-CH i CHCH 0- CH--O/ \R2 Column 2, lines 35-55, in the table under the heading "Time Required for Reaction", third entry should read ---1\To reaction in 18 hours--.

Column 2, lines 70-75, the formula should. read:

I base OCH-'O\ /R 2R -CH CHO oac- CHO HO C& 1 CH- OH 2 c -CH--O/ \R Signed and sealed this 28th day of November 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents TEC 10261 

2. The compound of claim 1 wherein R1 and R2 are methyl groups.
 3. Hexahydro-3,3,6,6-tetramethylfuro(3,2-b)furan-2,5-diol.
 4. A method for preparing a bicyclic furofuran-diol having the structure
 5. The process of claim 4 wherein the catalyst is sodium ethoxide.
 6. The process of claim 5 wherein bicyclic compound contacted is tetrahydro-2-isopropyl-6,6-dimethylfuro(2,3-d)-1,3-dioxol-5-ol. 